⇔ Symmetry
Mirror magic: find the matching halves!
▶ Play Door 14What is Symmetry?
A shape is SYMMETRICAL when one half is the mirror image of the other half.
The line that divides it is called the LINE OF SYMMETRY.
Fold a symmetrical shape on this line and the two halves match perfectly!
Worked example
Problem: If you fold a square in half from top to bottom, do the halves match? (yes or no)
- A square folded in the middle gives two equal rectangles.
- They match perfectly, so yes.
Answer: yes
Folding Activities
Folding is the easiest symmetry test.
Fold a paper heart down the middle: both sides match!
A circle can be folded in half in ANY direction: it has many lines of symmetry.
Worked example
Problem: How many equal halves does one fold make?
- One fold divides a shape into two parts.
- If symmetrical, both are equal: 2 halves.
Answer: 2
Symmetrical Things Around Us
Butterflies have matching wings: symmetrical!
Your face, a ladder, the letters A, H, M, O, T are symmetrical.
The letters F, G, J, P are NOT symmetrical.
Worked example
Problem: Is a butterfly symmetrical? (yes or no)
- Left wing and right wing are mirror images.
- So yes, it is symmetrical.
Answer: yes